Progress Report by Tong Jun Qun - Week 4
Week 4 29th August to 4th September The project was introduced to me on the 29th August, Monday during a briefing where I met up with Jeffrey and Kasun, the two PHD students who will be my mentors for this project. Prior to this meeting, I had read up on the project documentation Jeffrey sent over while I was on my overseas internship in the States. In addition, I watched several videos on YouTube, including Jeffrey’s presentation at Tedtalks last year as well as a live demonstration of the project. During the meeting, we discussed the project in its current state and the future improvements/suggestions that we can implement. The current setup achieves sensing via the use of a neodymium magnet that is attached to a wand and an array of six Hall Effect sensors overlayed on top of six electromagnets. We call this mode of sensing “Rare Earth Centric” sensing. A future implementation we dub hall effect centric sensing will do away with the hall effect sensor array and the neodymium magnet wand. Instead, only one Hall Effect sensor will be used as the primary input device. It will be embedded in an attachment that can be worn easily on the hand, more likely in the form of a ring or a glove. Each of the six electromagnets will be set to a different frequency via a function generator. It is hoped that the system will be able to discern the different electromagnets through the use of the Hall Effect sensor, allowing us to achieve the same effect as the previous setup, sans the haptic feedback due to the lack of a repelling force between the electromagnet and the neodymium magnet on the wand in the first setup. The trade off is that we can achieve sensing that is not as messy as the first setup. The ferrofluid have a tendency to be attracted the neodymium magnet on the wand, making the implementation a messy and uncomfortable experience for the user. Once the second setup has been completed, the team can proceed on to the user study in order to evaluate the two feedback modality, one with haptic feedback and one that uses rare earth centric sensing (swapping the neodymium magnet with a Hall Effect sensor). To get the setup running, I will need to familiarise myself with the technical aspects of the setup. As such, I had Kasun bring me up to speed with the technical aspects of the project, such as the operation of the ATMEGA 2560 microcontroller, the neodymium magnet and electromagnets. A deeper understanding of the system, including power wave modulation (PWM) and analog to digital converter (ADC) was gained later in the week through the datasheets and documentation. Objective Checklist *To fully understand the workings of Liquid Tangible User Interface. *To understand the firmware and microcontroller datasheet *Understand the operation of the Hall Effect sensor *Setting the hardware for the 2nd setup *Read through the C code that has been written so far for the ATMEGA 2560 microcontroller